Skip to content

Commit

Permalink
mac80211: fix virtual interfaces vs. injection
Browse files Browse the repository at this point in the history 
Currently, virtual interface pointers passed to drivers might be
from monitor interfaces and as such completely uninitialised
because we do not tell the driver about monitor interfaces when
those are created. Instead of passing them, we should therefore
indicate to the driver that there is no information; do that by
passing a NULL value and adjust drivers to cope with it.

As a result, some mac80211 API functions also need to cope with
a NULL vif pointer so drivers can still call them unconditionally.

Also, when injecting frames we really don't want to pass NULL all
the time, if we know we are the source address of a frame and have
a local interface for that address, we can to use that interface.
This also helps with processing the frame correctly for that
interface which will help the 802.11w implementation. It's not
entirely correct for VLANs or WDS interfaces because there the MAC
address isn't unique, but it's already a lot better than what we
do now.

Finally, when injecting without a matching local interface, don't
assign sequence numbers at all.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
  • Loading branch information
Johannes Berg authored and John W. Linville committed Sep 15, 2008
1 parent 9c31fd6 commit 25d834e
Show file tree
Hide file tree
Showing 5 changed files with 101 additions and 25 deletions.
3 changes: 2 additions & 1 deletion drivers/net/wireless/mac80211_hwsim.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -258,7 +258,8 @@ static int mac80211_hwsim_tx(struct ieee80211_hw *hw, struct sk_buff *skb)

txi = IEEE80211_SKB_CB(skb);

hwsim_check_magic(txi->control.vif);
if (txi->control.vif)
hwsim_check_magic(txi->control.vif);
if (txi->control.sta)
hwsim_check_sta_magic(txi->control.sta);

Expand Down
21 changes: 13 additions & 8 deletions drivers/net/wireless/rt2x00/rt2x00queue.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -155,7 +155,6 @@ static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
{
struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
struct rt2x00_intf *intf = vif_to_intf(tx_info->control.vif);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
struct ieee80211_rate *rate =
ieee80211_get_tx_rate(rt2x00dev->hw, tx_info);
Expand Down Expand Up @@ -278,16 +277,22 @@ static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
* sequence counter given by mac80211.
*/
if (tx_info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
spin_lock_irqsave(&intf->seqlock, irqflags);
if (likely(tx_info->control.vif)) {
struct rt2x00_intf *intf;

if (test_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags))
intf->seqno += 0x10;
hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
hdr->seq_ctrl |= cpu_to_le16(intf->seqno);
intf = vif_to_intf(tx_info->control.vif);

spin_unlock_irqrestore(&intf->seqlock, irqflags);
spin_lock_irqsave(&intf->seqlock, irqflags);

__set_bit(ENTRY_TXD_GENERATE_SEQ, &txdesc->flags);
if (test_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags))
intf->seqno += 0x10;
hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
hdr->seq_ctrl |= cpu_to_le16(intf->seqno);

spin_unlock_irqrestore(&intf->seqlock, irqflags);

__set_bit(ENTRY_TXD_GENERATE_SEQ, &txdesc->flags);
}
}

/*
Expand Down
1 change: 1 addition & 0 deletions include/net/mac80211.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -330,6 +330,7 @@ struct ieee80211_tx_info {

union {
struct {
/* NB: vif can be NULL for injected frames */
struct ieee80211_vif *vif;
struct ieee80211_key_conf *hw_key;
struct ieee80211_sta *sta;
Expand Down
64 changes: 60 additions & 4 deletions net/mac80211/tx.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -624,7 +624,14 @@ ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
u8 *qc;
int tid;

/* only for injected frames */
/*
* Packet injection may want to control the sequence
* number, if we have no matching interface then we
* neither assign one ourselves nor ask the driver to.
*/
if (unlikely(!info->control.vif))
return TX_CONTINUE;

if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
return TX_CONTINUE;

Expand Down Expand Up @@ -849,7 +856,6 @@ __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
sband = tx->local->hw.wiphy->bands[tx->channel->band];

skb->do_not_encrypt = 1;
info->flags |= IEEE80211_TX_CTL_INJECTED;
tx->flags &= ~IEEE80211_TX_FRAGMENTED;

/*
Expand Down Expand Up @@ -981,7 +987,7 @@ __ieee80211_tx_prepare(struct ieee80211_tx_data *tx,

/* process and remove the injection radiotap header */
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
if (unlikely(sdata->vif.type == NL80211_IFTYPE_MONITOR)) {
if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED)) {
if (__ieee80211_parse_tx_radiotap(tx, skb) == TX_DROP)
return TX_DROP;

Expand Down Expand Up @@ -1300,6 +1306,11 @@ int ieee80211_master_start_xmit(struct sk_buff *skb,
struct ieee80211_sub_if_data *osdata;
int headroom;
bool may_encrypt;
enum {
NOT_MONITOR,
FOUND_SDATA,
UNKNOWN_ADDRESS,
} monitor_iface = NOT_MONITOR;
int ret;

if (skb->iif)
Expand Down Expand Up @@ -1335,6 +1346,50 @@ int ieee80211_master_start_xmit(struct sk_buff *skb,
IEEE80211_IFSTA_MESH_CTR_INC(&osdata->u.mesh,
fwded_frames);
}
} else if (unlikely(osdata->vif.type == NL80211_IFTYPE_MONITOR)) {
struct ieee80211_sub_if_data *sdata;
struct ieee80211_local *local = osdata->local;
struct ieee80211_hdr *hdr;
int hdrlen;
u16 len_rthdr;

info->flags |= IEEE80211_TX_CTL_INJECTED;
monitor_iface = UNKNOWN_ADDRESS;

len_rthdr = ieee80211_get_radiotap_len(skb->data);
hdr = (struct ieee80211_hdr *)skb->data + len_rthdr;
hdrlen = ieee80211_hdrlen(hdr->frame_control);

/* check the header is complete in the frame */
if (likely(skb->len >= len_rthdr + hdrlen)) {
/*
* We process outgoing injected frames that have a
* local address we handle as though they are our
* own frames.
* This code here isn't entirely correct, the local
* MAC address is not necessarily enough to find
* the interface to use; for that proper VLAN/WDS
* support we will need a different mechanism.
*/

rcu_read_lock();
list_for_each_entry_rcu(sdata, &local->interfaces,
list) {
if (!netif_running(sdata->dev))
continue;
if (compare_ether_addr(sdata->dev->dev_addr,
hdr->addr2)) {
dev_hold(sdata->dev);
dev_put(odev);
osdata = sdata;
odev = osdata->dev;
skb->iif = sdata->dev->ifindex;
monitor_iface = FOUND_SDATA;
break;
}
}
rcu_read_unlock();
}
}

may_encrypt = !skb->do_not_encrypt;
Expand All @@ -1355,7 +1410,8 @@ int ieee80211_master_start_xmit(struct sk_buff *skb,
osdata = container_of(osdata->bss,
struct ieee80211_sub_if_data,
u.ap);
info->control.vif = &osdata->vif;
if (likely(monitor_iface != UNKNOWN_ADDRESS))
info->control.vif = &osdata->vif;
ret = ieee80211_tx(odev, skb);
dev_put(odev);

Expand Down
37 changes: 25 additions & 12 deletions net/mac80211/util.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -231,16 +231,21 @@ __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
struct ieee80211_rate *rate)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
struct ieee80211_sub_if_data *sdata;
u16 dur;
int erp;
bool short_preamble = false;

erp = 0;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
if (vif) {
sdata = vif_to_sdata(vif);
short_preamble = sdata->bss_conf.use_short_preamble;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
}

dur = ieee80211_frame_duration(local, frame_len, rate->bitrate, erp,
sdata->bss_conf.use_short_preamble);
short_preamble);

return cpu_to_le16(dur);
}
Expand All @@ -252,21 +257,25 @@ __le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_rate *rate;
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
struct ieee80211_sub_if_data *sdata;
bool short_preamble;
int erp;
u16 dur;
struct ieee80211_supported_band *sband;

sband = local->hw.wiphy->bands[local->hw.conf.channel->band];

short_preamble = sdata->bss_conf.use_short_preamble;
short_preamble = false;

rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];

erp = 0;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
if (vif) {
sdata = vif_to_sdata(vif);
short_preamble = sdata->bss_conf.use_short_preamble;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
}

/* CTS duration */
dur = ieee80211_frame_duration(local, 10, rate->bitrate,
Expand All @@ -289,20 +298,24 @@ __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_rate *rate;
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
struct ieee80211_sub_if_data *sdata;
bool short_preamble;
int erp;
u16 dur;
struct ieee80211_supported_band *sband;

sband = local->hw.wiphy->bands[local->hw.conf.channel->band];

short_preamble = sdata->bss_conf.use_short_preamble;
short_preamble = false;

rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];
erp = 0;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
if (vif) {
sdata = vif_to_sdata(vif);
short_preamble = sdata->bss_conf.use_short_preamble;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
}

/* Data frame duration */
dur = ieee80211_frame_duration(local, frame_len, rate->bitrate,
Expand Down

0 comments on commit 25d834e

Please sign in to comment.